The present invention relates to an indicating plate for solar cell included in an indicating plate structure for solar cell comprising a solar battery (solar cell) housed in a watch, the solar cell being capable of converting light energy to electric energy, and an indicating plate (dial) for solar watch arranged on a front side of the solar cell. More particularly, the present invention is concerned with an indicating plate for solar watch or indicating plate for EL (electro-luminescence) watch that enables not only the attainment of a design variation such as coloring and multicoloring but also high quality and superior appearance.
It is common practice to employ a solar cell as a power source for watches, desktop electronic calculators and portable radio sets. This solar cell is generally constructed of, for example, amorphous silicon and converts light energy to electric energy. In view of this function, the solar cell must be arranged in a position upon which light is incident, i.e., a surface position such that the solar cell is directly visible from outside.
The solar cell is commonly used in an indicating plate structure for wristwatch, which is constructed so that, referring to FIGS. 36 and 37, four solar cells 632 which are fan-shaped in a plan view are arranged, with insulating band 633 therebetween, on an upper surface of wristwatch module 631 and so that translucent resin thin film layer 635 is laminated onto each of the solar cells 632 with transparent plate 634 of a transparent polycarbonate (polycarbonic ester) resin or acrylic resin interposed therebetween.
In this indicating plate structure for solar watch, however, the solar cells 632 are generally brown or dark-blue, so that, for example, the solar cells disposed under the transparent plate are viewed through the transparent plate. Thus, the dial takes on the color of the solar cells. Further, there is insulating band 633 between neighboring solar cells 632, so that the insulating bands 633 appear as cross lines. Thus, not only is the design inclusive of color tone extremely restricted but also the appearance is degraded to thereby lower the commercial value.
In contrast, a watch was proposed in which, for example, an interference filter was disposed on a front side of a solar cell to thereby prevent direct viewing of the solar cell. However, problems were encountered such that the supply of light energy to the solar cell was hampered and such that the appearance quality of the watch dial was poor.
For solving these problems, for example, Japanese Patent Publication No. 5(1993)-38464 disclosed a colored solar cell comprising a solar cell, a color filter disposed on a front side of the solar cell and capable of transmitting light having a wavelength within a region contributing to power generation of the solar cell, and a color diffusing layer composed of a scattering layer disposed between the solar cell and the color filter, which scattering layer was capable of transmitting portion of the light transmitted through the color filter and scattering the rest of the light in all directions.
A white diffusion plate was employed as this scattering layer, and it was suggested to use as the white diffusion plate, for example, an acrylic milk white plate, a half mirror coated with a matting clear lacquer, a glass having one side roughened by blasting or a white diffusion plate having a mirror formed of, for example, aluminum in a stripe or net pattern on a side opposite to plastic.
However, in this prior art, the use of the acrylic milk white plate as the scattering layer disenables obtaining a metal tone favored in an indicating plate of wristwatch and capable of imparting an appearance of superior quality. Further, burrs occur at the time of working, thereby necessitating deburring. Accordingly, the process is complicated and the cost is increased. With respect to the half mirror coated with a matting clear lacquer, half mirror treatment and coating are required to thereby complicate the process. Further, it is probable that, depending on coating operation, the film thickness becomes nonuniform to thereby cause a dispersion of transmission factor with the result that mottling occurs. Moreover, with respect to the glass having one side roughened by blasting or the white diffusion plate having a mirror formed of, for example, aluminum in a stripe or net pattern on a side opposite to plastic, blasting and mirror treatment are required to thereby complicate the process. Further, depending on these treatments, the problem is encountered such that the film thickness and irregularity degree become nonuniform to thereby invite a dispersion of transmission factor and a mottling. Furthermore, all the above materials have a problem such that the appearance quality thereof as a watch dial is poor.
At any rate, the interposition of the above scattering layer between the color filter and the solar cell unfavorably requires a complicated process, invites a dispersion of transmission factor leading to a deterioration of power generation. performance and invites mottling and a deterioration of appearance quality due to the property of material per se.
On the other hand, in the use of the conventional indicating plate for solar watch, it is difficult to view time or other information on the indicating plate in the night or other nonilluminated dark environment, thereby necessitating separately equipping the watch frame with an illuminator or the like.
An EL (electro-luminescence) equipped watch was already developed in which an EL cell having a transparent resin plate provided with transparent electrodes on its upper and lower surfaces, in which a phosphor such as zinc sulfide was dispersed, for the purpose of viewing time or other information on the indicating plate in the night or other nonilluminated dark environment was arranged under the indicating plate. In this watch as well, the same problem was encountered that the underlying EL cell was visible through the indicating plate.
Moreover, each of the conventional indicating plates for watches was composed of a single material, so that the entirety of the indicating plate exhibited only a single color, thereby disenabling a design diversification. In particular, with respect to the conventional indicating plate for solar watch and, indicating plate for EL watch, one composed of a precious stone, a shell or a combination thereof with a metal has not been developed, and no indicating plate enabling a design diversification and having a high quality and an appearance of superior quality has been proposed.
The present invention has been made taking the above problems into account. It is an object of the present invention to provide an indicating plate for solar watch through which, for example, the insulating band cross lines and solar cell positioned under the indicating plate are not visible, which indicating plate can be colored, enables greatly increased design variation inclusive of a high-quality pattern and tone (delicate color shade) and has an appearance of superior quality which enhances commercial value.
It is a further object of the present invention to provide an indicating plate for watch, especially, an indicating plate for solar watch or indicating plate for EL equipped watch through which, for example, the EL cell, insulating band cross lines and solar cell positioned under the indicating plate are not visible, which indicating plate can be colored or multicolored, enables greatly increased design variation inclusive of tone, makes a high-grade impression produced by the use of a fine member such as a precious stone and has an appearance of superior quality which enhances commercial value.
It is still a further object of the present invention to provide an indicating plate for watch, which is luminescent because of persistence characteristic, so that time can be viewed thereon in the night or other dark environment.
The present invention has been made with a view toward solving the above problems of the prior art and attaining the above objects. Accordingly, there is provided an indicating plate structure for solar watch comprising a solar cell housed in a watch and an indicating plate for solar watch arranged on a front side of the solar cell, the above indicating plate comprising a color diffusion plate adapted to transmit portion of light having a wavelength within a range capable of causing a solar cell housed under the indicating plate to generate power, out of light at least incident upon the indicating plate, through the indicating plate downward, the above color diffusion plate adapted to render difficult viewing of the solar cell from outside through the indicating plate and adapted to impart color tone to the indicating plate.
In another constitution of the present invention, the indicating plate for solar watch comprises an indicating plate substrate composed of a transparent resin and a light storing fluorescent layer formed on a light-incident-side surface of the indicating plate substrate, the above light storing fluorescent layer comprising a light diffusing agent and, as a coloring light diffusing agent, a light storing fluorescent material. Thus, both the above light diffusing function and coloring function can be effectively performed. That is, not only can the indicating plate be colored due to the tone (white tone) of the light storing fluorescent material to thereby enhance the visibility of the indicating plate but also the underlying solar cell, cross line, etc. are not visible through the indicating plate. Moreover, high-luminance persistence characteristic can be exerted by an excitation spectrum of slight light for a prolonged period of time because of the formation of long-persistance-type light storing fluorescent material on a front side of the indicating plate substrate to thereby enable viewing time in the night or other dark environment. Furthermore, the power generation of the solar cell is not obstructed because portion of light required for the solar cell to generate power, out of light incident upon the indicating plate, is transmitted through the indicating plate downward.
In the indicating plate for solar watch according to a further constitution of the present invention, the above indicating plate substrate composed of a transparent resin contains a light storing fluorescent material as a coloring light diffusing agent, so that both the above light diffusing function and coloring function can be more effectively performed.
In the indicating plate for solar watch according to still a further constitution of the present invention, both the light storing fluorescent layer and the indicating plate substrate composed of a transparent resin contain a light storing fluorescent material as a coloring light diffusing agent, so that both the above light diffusing function and coloring function can be still more effectively performed.
In still a further constitution of the present invention, the indicating plate for solar watch comprises an indicating plate substrate composed of a transparent resin and a colored layer formed on a light-incident-side surface of the indicating plate substrate, the above colored layer comprising a coloring agent. Thus, not only can the indicating plate be colored by the coloring layer but also the coloring agent per se has some diffusing capability, so that the underlying solar cell, etc. are not visible through the indicating plate.
In still a further constitution of the present invention, the indicating plate for solar watch comprises an indicating plate substrate composed of a transparent resin and a colored layer formed on a solar-cell-side surface of the indicating plate substrate, the above colored layer comprising a coloring agent, the above indicating plate substrate having minute irregularities formed on its light-incident-side; surface. Thus, not only can the indicating plate be colored by the coloring layer but also the coloring agent per se has some diffusing capability, so that the underlying solar cell, etc. are rendered invisible through the indicating plate by the diffusing function of the coloring agent per se and the light diffusing function of the minute irregularities.
In still a further constitution of the present invention, the indicating plate for solar watch comprises an indicating plate substrate composed of a transparent resin containing a dye or pigment as a coloring agent, the above indicating plate substrate having minute irregularities with light diffusing function formed on its light-incident-side surface. Thus, not only can the indicating plate be colored by the dye or pigment contained in the transparent resin but also the underlying solar cell, etc. are rendered invisible through the indicating plate by the diffusing function of the coloring agent per se and the light diffusing function of the minute irregularities. In the indicating plate for solar watch according to still a further constitution of the present invention, the transparent resin further contains a light diffusing agent, so that the underlying solar cell, etc. are more effectively rendered invisible through the indicating plate.
In still a further constitution of the present invention, the indicating plate for solar watch comprises an indicating plate substrate composed of a transparent resin containing a light diffusing agent and a reflecting layer formed on a solar-cell-side surface of the indicating plate substrate, the reflecting layer capable of performing a light diffusing function, and the indicating plate substrate having minute irregularities formed on its light-incident-side surface. This reflecting layer is a thin film capable of reflecting portion of light and absorbing other portion of light while transmitting the rest of light, so that the reflecting layer functions as a coloring agent. Therefore, not only is the tone of the reflecting layer recognized as that of the indicating plate but also the underlying solar cell, etc. are not visible through the indicating plate.
In still a further constitution of the present invention, the indicating plate for solar watch comprises a colored translucent substrate capable of transmitting light, a pattern layer disposed on a front side of the colored translucent layer and a colored thin film layer disposed on a back side of the colored translucent substrate.
By virtue of this constitution, portion of light of a wavelength range of series different from the color of the colored translucent substrate out of the light incident upon the colored translucent substrate is absorbed by the colored translucent substrate. Portion of the light of a wavelength range of the same series as the color of the colored translucent substrate is transmitted through the colored thin film layer to reach the solar cell, thereby contributing to power generation of the solar cell. The rest of the light is reflected toward the surface. This is because the colored thin film layer is an extremely thin film, so that it performs the function of transmitting portion of light while reflecting the rest of the light.
The light having been reflected by the colored thin film layer has directivity and is inhomogeneous. However, this light is diffused by the dye or pigment mixed in the colored translucent substrate and the pattern layer and reaches the eyes of the viewer. Therefore, the viewer views, on the entire surface of the colored translucent substrate, the pattern layer together with a delicate hue comprising a uniform combination of the color of the colored thin film layer with the color of the colored translucent substrate as a base. As a result, the brown or dark-blue solar cell and insulating band cross lines are not viewed through the indicating plate.
Therefore, designing can be diversified to thereby realize the same design expression as made in the conventional indicating plate. Thus, not only is a design variation inclusive of a tone and pattern imparting a high-grade feeling markedly increased but also a delicate hue can be provided so that the appearance quality is enhanced to thereby contribute to an increase of commercial value.
In the indicating plate for solar watch according to still a further constitution of the present invention, the above colored thin film layer is a metallized layer.
By virtue of this constitution, portion of light of a wavelength range of a different series from the color of the colored translucent substrate out of the light incident upon the colored translucent substrate is absorbed by the colored translucent substrate. Portion of the light of a wavelength range of the same series as the color of the colored translucent substrate is transmitted through the metallized layer to reach the solar cell, thereby contributing to power generation of the solar cell. The rest of the light is reflected toward the surface. This is because the metallized layer is an extremely thin film, so that it performs the function of transmitting portion of light while reflecting the rest of the light.
The light having been reflected by the metallized layer has directivity and is inhomogeneous. However, this light is diffused by the dye or pigment mixed in the colored translucent substrate and the pattern layer and reaches the eyes of the viewer. Therefore, the viewer views, on the entire surface of the colored translucent substrate, the pattern layer together with a delicate hue comprising a uniform combination of the color of the metallized layer with the color of the colored translucent substrate as a base. As a result, the brown or dark-blue solar cell and insulating band cross lines are not visible through the indicating plate.
Therefore, designing can be diversified to thereby realize the same design expression as made in the conventional indicating plate. Thus, not only is a design variation inclusive of a tone and pattern imparting a high-grade feeling markedly increased but also a delicate hue can be provided so that the appearance quality is enhanced to thereby contribute to an increase of commercial value.
In still a further constitution of the present invention, the indicating plate for solar watch comprises a transparent substrate capable of transmitting light, a pattern layer disposed on a front side of the transparent substrate, a diffusion layer disposed on a back side of the transparent substrate and a colored thin film layer disposed on the diffusion layer.
By virtue of this constitution, portion of the light incident upon the transparent substrate is transmitted through the diffusion layer and the colored thin film layer to reach the solar cell, thereby contributing to power generation of the solar cell. The rest of the light is diffused and reflected toward the surface by the colored thin film layer and diffusion layer disposed on a back side of the transparent substrate. This is because the colored thin film layer is an extremely thin film, so that it performs the function of transmitting portion of light while reflecting the rest of the light. The light having been diffused and reflected by the diffusion layer and colored thin film layer has directivity and is inhomogeneous. However, this light is further diffused (scattered) by the pattern layer disposed on a surface of the transparent substrate. Therefore, the viewer views, homogeneously on the entire surface of the transparent substrate, the pattern layer together with the color of the colored thin film layer. As a result, the brown or dark-blue solar cell and insulating band cross lines are not viewed through the indicating plate.
Therefore, designing can be diversified to thereby realize the same design expression as made in the conventional indicating plate. Thus, not only is a design variation inclusive of a tone and pattern imparting a high-grade feeling markedly increased but also a delicate hue can be provided so that the appearance quality is enhanced to thereby contribute to an increase of commercial value.
In the indicating plate for solar watch according to still a further constitution of the present invention, the transparent substrate, the pattern layer and the diffusion layer are monolithically formed.
By virtue of this constitution, not only can the same functions as those of the above invention be performed but also, because of the monolithic formation of the transparent substrate, the pattern layer and the diffusion layer, the pattern layer can be formed into, for example, Piazzi cut or glory-of-rising-sun pattern with the result that a design variation inclusive of a tone and pattern imparting a high-grade feeling is markedly increased so that the appearance quality is enhanced to thereby contribute to an increase of commercial value.
In the indicating plate for solar watch according to still a further constitution of the present invention, the colored thin film layer is a metallized layer.
By virtue of this constitution, portion of the light incident upon the transparent substrate is transmitted through the diffusion layer and the metallized layer to reach the solar cell, thereby contributing to power generation of the solar cell. The rest of the light is diffused and reflected toward the surface by the metallized layer and diffusion layer disposed on a back side of the transparent substrate. This is because the metallized layer is an extremely thin film, so that it performs the function of transmitting portion of light while reflecting the rest of the light. The light having been diffused and reflected by the diffusion layer and metallized layer has directivity and is inhomogeneous. However, this light is further diffused (scattered) by the pattern layer disposed on a surface of the transparent substrate. Therefore, the viewer views, homogeneously on the entire surface of the transparent substrate, the pattern layer together with the color of the metallized layer. As a result, the brown or dark-blue solar cell and insulating band cross lines are not viewed through the indicating plate.
Therefore, designing can be diversified to thereby realize the same design expression as made in the conventional indicating plate. Thus, not only is a design variation inclusive of a tone and pattern imparting a high-grade feeling markedly increased but also a delicate hue can be provided so that the appearance quality is enhanced to thereby contribute to an increase of commercial value.
In another aspect of the present invention, there is provided a disklike indicating plate for watch adapted to be assembled in a watch frame, which has at least a portion thereof exposed at its front side composed of an indicating member comprising at least two different types of members and at least one of which is capable of transmitting light downward.
In the indicating plate for watch according to a particular constitution of this invention, the indicating member comprises an inner-boundary-side member and a peripheral-side member.
In this indicating plate for watch, the inner-boundary-side member and peripheral-side member may be composed of respective different materials selected from among appropriate combinations of natural materials, for example, precious stones such as sapphire, blue pearl, onyx and tiger""s-eye, shells such as white pearl oyster shell, glass and ceramics such as Al2O3 and synthetic materials, for example, metals such as titanium, SUS 304 and other stainless steels and brass, german silver and other copper alloys and plastics such as polycarbonate and polyacetal resins.
In the indicating plate for watch according to another constitution of the present invention, the inner-boundary-side member is fitted in a central opening provided in the peripheral-side member. In this constitution, the indicating plate can be colored and multicolored. Appropriate selection of materials enables not only inhibiting the view of the solar cell, etc. through the indicating plate but also markedly increasing a design variation inclusive of tone. Moreover, the use of a high-quality member such as a precious stone enables providing the indicating plate for watch that imparts a high-grade feeling and ensures an excellent appearance quality to thereby ensure a high commercial value.
In the indicating plate for watch according to a further constitution of the present invention, the inner-boundary-side member is fitted in a central recess provided in the peripheral-side member. In this constitution as well, the same effects can be exerted. Furthermore, by virtue of the positioning (piling) of the peripheral-side member under the inner-boundary-side member, not only is viewing of the solar cell through the indicating plate prevented but also a strength increase is attained. Depending on combination of materials, the tones of peripheral-side member and inner-boundary-side member lie one on the other so that a delicate hue can be bred in the center of the indicating plate to thereby increase a design variation.
In the indicating plate for watch according to still a further constitution of the present invention, the inner-boundary-side member a central protrusion provided in the inner-boundary-side member is fitted in a central opening provided in the peripheral-side member so that the inner-boundary-side member is coupled with the peripheral-side member. In this constitution as well, the same effects can be exerted. Furthermore, by virtue of the positioning (piling) of the inner-boundary-side member under the peripheral-side member, not only is viewing of the solar cell through the indicating plate prevented but also a strength increase is attained. Depending on combination of materials, the tones of inner-boundary-side member and peripheral-side member lie one on the other so that a delicate hue can be bred in the periphery of the indicating plate to thereby increase a design variation.
In the indicating plate for watch according to still a further constitution of the present invention, a base material of the same material as that of the inner-boundary-side member and the peripheral-side member is bonded to backs of the inner-boundary-side member and the peripheral-side member. In this constitution as well, the same effects can be exerted. Furthermore, by virtue of the positioning (piling) of the base material under the peripheral-side member and inner-boundary-side member, not only is a further strength increase attained but also viewing of the solar cell through the indicating plate is prevented. Depending on combination of materials, the tone of the peripheral-side member and inner-boundary-side member and the tone of the base material lie one on the other so that a delicate hue can be bred in the entirety of the indicating plate to thereby increase a design variation.
In the indicating plate for watch according to still a further constitution of the present invention, the peripheral-side member and base material are composed of a natural material selected from among precious stones, shells, glasses and ceramics, and a periphery of the peripheral-side member and base material is fitted with a ringlike mounting member composed of a metal or a plastic and provided with a fixing part for fixing the indicating plate to a watch frame. In still a further constitution of the present invention, a back side of the mounting member is provided with a collar part that is protrudent inward from a circumferential part of a central opening provided in the mounting member, the above central opening and collar part forming a recess, in which the peripheral-side member and base material are fitted in the recess. When a natural material such as a precious stone, a shell or a ceramic is used as the peripheral-side member and base material, it is difficult to effect a working such as protrusion or notch for fixing the indicating plate to a watch frame, thereby inviting a cost increase. However, the mounting member of, for example, a metal or a plastic can be easily worked, so that a spacing corresponding to the thickness (100 to 200 xcexcm) of the collar part of the mounting member is provided between the indicating plate members and the module 4 arranged thereunder. Therefore, even if the module is deformed, for example, at the time of impact, the influence of the deformation is avoided and the indicating plate for watch will not suffer from cracking or damaging. Thus, neither appearance nor product quality is deteriorated.
The indicating plate for watch according to still a further constitution of the present invention is an indicating plate for solar watch included in an indicating plate structure for solar watch comprising a solar cell housed in a watch and an indicating plate for solar watch arranged on a front side of the solar cell. In still a further constitution of the present invention, the indicating plate for watch has a transmission factor of light contributing to power generation of 10 to 60%. In this constitution, not only are the functions of the solar watch ensured but also the underlying solar cell, etc. are not viewed through the indicating plate to thereby realize the above increase of design variation.